Pan American Journal Investigación original / Original research of Public Health

Health inequalities by gradients of access to water and sanitation between countries in the Americas, 1990 and 2010

Oscar J. Mújica,1 Mariana Haeberer,2 Jordan Teague,3 Carlos Santos-Burgoa,3 and Luiz Augusto Cassanha Galvão1

Suggested citation Mújica OJ, Haeberer M, Teague J, Santos-Burgoa C, Galvão LAC. Health inequalities by gradients of access to water and sanitation between countries in the Americas, 1990 and 2010. Rev Panam Salud Publica. 2015; 2015;38(5):347–54.

ABSTRACT Objective. To explore distributional inequality of key health outcomes as determined by access coverage to water and sanitation (WS) between countries in the Region of the Americas. Methods. An ecological study was designed to explore the magnitude and change-over-time of standard gap and gradient metrics of environmental inequalities in health at the country level in 1990 and 2010 among the 35 countries of the Americas. Access to drinking water and access to improved sanitation facilities were selected as equity stratifiers. Five depen- dent variables were: total and healthy life expectancies at birth, and infant, under-5, and maternal mortality. Results. Access to WS correlated with survival and mortality, and strong gradients were seen in both 1990 and 2010. Higher WS access corresponded to higher life expectancy and healthy life expectancy and lower infant, under-5, and maternal mortality risks. Burden of life lost was unequally distributed, steadily concentrated among the most environmentally disad- vantaged, who carried up to twice the burden than they would if WS were fairly distributed. Population averages in life expectancy and specific mortality improved, but whereas absolute inequalities decreased, relative inequalities remained mostly invariant. Conclusions. Even with the Region on track to meet MDG 7 on water and sanitation, large environmental gradients and health inequities among countries remain hidden by Regional averages. As the post-2015 development agenda unfolds, policies and actions focused on health equity—mainly on the most socially and environmentally deprived—will be needed in order to secure the right for universal access to water and sanitation.

Key words Health inequalities; water; sanitation; environmental health; social determinants of health; Millennium Development Goals; Sustainable Development Goals; Americas.

The right to safe and clean drinking situation and trends in water, sanitation, 1 Special Program on Sustainable Development and Health Equity, Pan American Health Organization/ water and sanitation has been explicitly and hygiene (WS), declaring that the World Health Organization (PAHO/WHO), recognized by the United Nations (UN) as Region of the Americas has reached the Washington, DC, United States of America. Send correspondence to Oscar J. Mújica, email: a human right, essential for the full enjoy- Millennium Development Goal (MDG) [email protected] ment of life (1). In 2012, the World Health Target 7c for water and that it was on 2 Gender, Diversity, and Human Rights Unit, Organization (WHO)/UN Children’s Fund track to meet MDG Target 7c for sanita- PAHO/WHO, Washington, DC, United States. 3 Occupational and Environmental Risks Unit, (UNICEF) Joint Monitoring Programme tion by 2015 (2). That same year, the UN PAHO/WHO, Washington, DC, United States. released its global report on the current also released its Global Analysis and

Rev Panam Salud Publica 38(5), 2015 347 Original research Mújica et al. • Water, sanitation, and health inequalities in the Americas

Assessment of Sanitation and Drinking to drinking water and to sanitation facili- Venezuela. Collectively, these account Water Report (3) pointing to wide dispar­ ties—between countries of the Americas for 99.5% of the current estimated popu- ities in access to water and sanitation as in 1990 and 2010, i.e., the study’s “MDG lation of the Region of the Americas (11). the main challenge­ to extending and sus- time window.” taining services in the Americas, particu- Data analysis larly in Latin America and the Caribbean MATERIALS AND METHODS (LAC). In fact, this Region is known by its This study followed Tukey’s principle for huge social and environmental disparities Study design exploratory data analysis: it aimed at pat­ and health inequalities (4). tern extraction rather than causal associa- As reported in the Global Burden of An observational, ecological, country-­ tion (12). Standard inequality analyses (13) Disease Study (5), in 2010 LAC saw an level, secondary data-based study were performed using both abridged and aver­age of 4 000 premature deaths (4.5 per was designed to explore both the unabridged distributions of each health mil­lion) and 323.4 disability-adjusted life ­magnitude of and change-over-time outcome. The former was used to explore years lost per million attributable to the in core ­environmentally-determined absolute and relative gap inequality,­ cap­ lack of access to improved WS sources. health inequalities­ in the Region of the tured in range-based, Kuznets-like metrics Inadequate WS practices and services lead Americas in 1990, and in 2010. by subtracting and dividing, respectively, to a higher prevalence of waterborne dis­ the unbiased (­population weighted) health eases, such as acute diarrhea (mostly Data acquisition ­outcome estimators of the bottom (least among infants and children), hepatitis, ­advantaged) from the top (most advan­ typhoid and paratyphoid enteric fevers, Country data were obtained from taged) WS country quartiles. The absolute and intestinal parasites and other parasitic a number of institution-based, internally- gap inequality index retains the units of the diseases (6). Furthermore, the lack of access consistent, publicly-available data sour- health variable and has zero as its equity to improved sources of sanitation may ces, including the WHO/UNICEF Joint reference; the relative gap inequality index force individuals to defecate in the open— Monitoring Programme (2), PAHO is dimensionless and has the unity as its described by WHO as “the riskiest sanita­ Re­gional Core Health Data Initiative (11) equity reference. tion practice of all”—generating a major (which, in turn, contains several The unabridged distribution of each cause of ground water pollution, agricul­ interagency-­derived, MDG-related indi- health outcome was used to generate tural produce contamination, and disease cators, as well as UN population esti­ more robust summary measures of gra- transmission (7, 8). This context creates mates), the World Bank databank, and dient inequality. Absolute gradient in- severe detrimental effects on the health of from the Global Burden of Disease 2010 equality was captured by the slope index individuals and societies, leading to impover­ Study (5), available at the Institute for of inequality (SII), which corresponds ishment and destitution due to decreasing Health Metrics and Evaluation’s Global to the slope of the regression line obtai- economic and educational opportunities. Health Data Exchange. ned by regressing country-level health Access to water and sanitation can be The study variables selected for the outcome rates on a relative­ scale of considered the very epitome of an envi- study were survival and mortality ­WS-related social position (ridit), as defi- ronmental determinant of health. The de- indicators of public health relevance ned by the cumulative class interval mid- terminants of health—that is, the general with high quality data available. The point of the population ranked by the conditions and circumstances in which indepen­dent variables were two envi- equity stratifier. To account for intrinsic people are born, grow, live, work, and ronmental determinants/social­ strati- heteroskedasticity of aggregated data, age—play a central role in establishing fiers: access to drinking­ water and access the Maddala’s weighted least-squares and maintaining social position, thus de- to improved ­sanitation, according to the ­regression model was applied, as des- termining the distribution of health and standard definitions­ of WHO/UNICEF cribed elsewhere (14). Logarithmic data well-being (9). Under the eco-epidemiolo- (2). The dependent variables were five transformation was also tested to ac- gic paradigm (10), social inequalities are public health outcomes: life expectancy count for equity stratifier-health status considered “the causes of the causes” of at birth, healthy (disability-free) life ex- relationship skewness or non-­linearity, poor health outcomes; therefore, inequa­l­ pectancy at birth, infant mortality rate, when indicated. As an absolute measure- ities in access to WS must drive inequali- under-5 mortality rate, and maternal ment of inequality, the SII retains the ties in avoidable morbidity, mortality, mortality ratio. units of the health variable and has zero and survival. Evidence on the magnitude The units of analysis (n = 35) were ag- as its equity reference. and trends of those environmentally-­ gregated at the country level and corre­ Relative gradient inequality was cap­ determined inequalities in health is yet sponded to: Antigua and Barbuda, tured by the health concentration index lacking for the Region of the Americas. Argentina, Bahamas, Barbados, Belize, (HCI), a summary measure of dispropor- To help fill this gap, this study aimed to Bolivia, Brazil, Canada, Chile, Colombia, tionality between population and health explore the magnitude and change-over- Costa Rica, Cuba, Dominica, Dominican shares. It was computed by fitting, by non- time of inequalities in the distribution of Republic, Ecuador, El Salvador, Grenada, linear optimization, a Lorenz concentra- five core population health outcomes Guatemala, Guyana, Haiti, Honduras, tion curve equation (15) to the observed (total life expectancy, healthy life ex­ Jamaica, Mexico, Nicaragua, Panama, cumulative relative distributions of the pectancy, infant mortality, mortality­ under Paraguay, Peru, Saint Kitts and Nevis, population ranked by the equity stratifier 5 years of age, and maternal mortality) as Saint Lucia, Saint Vincent and the and the health outcome across the coun- driven by the unequal distribution of two Grenadines, Suriname, Trinidad and tries stud­ied, and numerically integrating­ key environmental determinants—access Tobago, United States, Uruguay, and the area under the curve. As a relative

348 Rev Panam Salud Publica 38(5), 2015 Mújica et al. • Water, sanitation, and health inequalities in the Americas Original research measurement of inequality, the HCI is the social gap/gradient was narrowing or of 80 measurements of health inequal­ dimensionless and has zero as its equity widening. ity computed, 73 (+91%) systematically,­ reference. All statistical analyses were per­ and non-trivially, departed from their Uncertainty was ascertained by comput­ formed in MS ExcelTM Solver and ToolPak equity reference. ing 95% confidence intervals (95%CI) for ­add-ins (Microsoft Corp., Redmond, Table 2 shows the summary distribu- all summary measures of health inequality.­ Washington, United States) using a semi-­ tion of each health outcome across quar­ To assess health inequality change-over-­ automated analytical template tool devel­ tiles of each equity stratifier, both in 1990 time, the average rate of change in the oped by PAHO for the exploratory data and in 2010, exposing—unrelentingly— magnitude of a given health inequality analysis of social inequalities in health the presence and persistence of the health metrics­ between the two time-­points was (available upon request). gradient: albeit auspiciously lessened computed. To characterize Regional lately, the lesser the access to water and/ scenar­ios of population health in the period RESULTS or sanitation, the poorer the health studied, health changes in mean popula- ­outcomes across countries. tion trends and social gap/gradients All four summary measures of health were simultaneously assessed, based on inequality (gap/gradient and absolute/ WS-related inequalities in life an analytical framework derived­ from relative) with their 95%CI, along with the expectancy Minujin and Delamonica’s approach (16). Regional average level for each of the five Four possible scenarios were discrimi­ health outcomes across the two equity The study found a 5-year average rise in nated, based on whether the Regional stratifiers at the two points in time (1990 life expectancy between 1990 and 2010 (from ­average was improving or worsening and and 2010) are shown in Table 1. Of a total 71.2 to 76.2 years of age) in the Region as a

TABLE 1. Change-over-time in health inequalities across environmental gradients, as defined by access to water and sanitation services, countries of the Americas (n = 29–35), 1990 and 2010

Access to drinking water Access to sanitation facilities 1990 2010 Average 1990 2010 Average 95%CIa 95%CI rate of 95%CI 95%CI rate of Health Point Point change in Point Point change in outcome Summary metrics value Lower Upper value Lower Upper inequalityb value Lower Upper value Lower Upper inequality Life Regional mean, years 71.2 69.7 72.7 76.2 75.0 77.4 expectancy Absolute gap index −11.0 −13.8 −8.1 §c −6.3 −9.8 −2.8 § 42.7 −11.6 −14.8 −8.4 § −7.7 −10.2 −5.3 § 33.6 at birth Relative gap index 0.85 0.74 0.97 § 0.92 0.79 1.05 −8.2 0.85 0.73 0.97 § 0.90 0.81 0.99 § −5.9 Slope index of inequality 12.8 9.3 16.2 § 8.9 5.7 12.1 § 30.5 13.1 9.7 16.4 § 10.8 8.4 13.1 § 17.4 Health concentration index −0.31 −0.44 −0.17 § −0.50 −0.38 −0.12 § −61.3 −0.37 −0.51 −0.22 § −0.37 −0.52 −0.23 § 0.0

Healthy life Regional mean, years 61.6 60.5 62.8 64.2 62.9 65.6 expectancy Absolute gap index −7.6 −10.9 −4.3 § −6.1 −13.0 0.7 19.7 −8.1 −11.5 −4.7 § −5.7 −11.6 0.3 30.4 at birth Relative gap index 0.88 0.74 1.03 0.91 0.61 1.20 −3.4 0.87 0.72 1.02 0.91 0.66 1.17 −4.6 Slope index of inequality 8.5 5.6 11.3 § 6.2 1.5 10.8 § 27.5 8.6 5.8 11.4 § 7.3 2.9 11.6 § 15.6 Health concentration index −0.33 −0.47 −0.18 § −0.29 −0.43 −0.14 § 12.1 −0.38 −0.54 −0.23 § −0.38 −0.53 −0.22 § 0.0

Infant Regional mean, per 1 000 LBd 29.0 28.6 29.4 13.2 13.0 13.5 mortality Absolute gap index 49.2 48.0 50.3 § 16.3 15.5 17.1 § 66.8 51.5 50.3 52.7 § 17.7 17.0 18.4 § 65.7 rate Relative gap index 6.29 5.99 6.61 § 2.56 2.45 2.69 § 59.3 6.54 6.23 6.87 § 3.73 3.53 3.94 § 43.0 Slope index of inequality −59.7 −73.0 −46.4 § −19.6 −27.9 −11.4 § 67.1 −59.8 −73.1 −46.6 § −22.2 −29.5 −14.8 § 62.9 Health concentration index −0.32 −0.43 −0.22 § −0.22 −0.33 −0.12 § 31.3 −0.38 −0.49 −0.27 § −0.28 −0.38 −0.17 § 26.3

Under-5 Regional mean, per 1 000 LB 36.1 35.7 36.6 16.3 16.1 16.6 mortality Absolute gap index 69.6 68.3 70.9 § 30.6 29.7 31.4 § 56.1 73.8 72.5 75.1 § 28.9 28.1 29.7 § 60.9 rate Relative gap index 7.24 6.93 7.56 § 3.58 3.44 3.73 § 50.6 7.61 7.29 7.95 § 4.87 4.64 5.11 § 36.0 Slope index of inequality −79.3 −97.0 −61.5 § −29.7 −48.7 −10.8 § 62.5 −79.3 −97.0 −61.5 § −32.2 −50.6 −13.7 § 59.4 Health concentration index −0.34 −0.45 −0.24 § −0.29 −0.40 −0.18 § 14.7 −0.39 −0.50 −0.28 § −0.32 −0.43 −0.21 § 17.9

Maternal Regional mean, per 100 000 LB 86.7 80.0 93.7 58.9 54.1 64.1 mortality Absolute gap index 289.7 267.6 311.8 § 97.8 81.9 113.8 § 66.2 277.5 255.9 299.0 § 93.4 79.4 107.4 § 66.3 ratio Relative gap index 16.75 12.49 22.47 § 3.75 2.97 4.72 § 77.6 23.36 16.31 33.47 § 5.00 3.83 6.55 § 78.6 Slope index of inequality −251.9 −344.3 −159.5 § −118.6 −153.3 −83.8 § 52.9 −244.2 −339.7 −148.6 § −102.0 −144.2 −59.8 § 58.2 Health concentration index −0.44 −0.58 −0.31 § −0.30 −0.43 −0.17 § 31.8 −0.48 −0.62 −0.35 § −0.28 −0.41 −0.14 § 41.7 Source: prepared by authors from the study results. a 95%CI = 95% confidence interval. b Average rate of change in inequality = (1990 pv – 2010 pv) / 1990 pv × 100. c § = non-trivially departed from its equity reference. d LB = live births.

Rev Panam Salud Publica 38(5), 2015 349 Original research Mújica et al. • Water, sanitation, and health inequalities in the Americas

TABLE 2. Health outcome distribution across quartiles of access to water and sanitation services, countries of the Americas (n = 29–35), 1990 and 2010

Year Access to drinking water Access to sanitation facilities Health outcome, units assessed Lowest Second Third Highest Lowest Second Third Highest Life expectancy at birth, years 1990 64.6 70.4 68.3 75.6 63.9 67.9 72.4 75.5 2010 71.1 73.6 76.8 77.4 72.0 74.2 75.5 79.7 Healthy life expectancy at birth, years 1990 56.6 61.2 59.5 64.2 56.1 59.7 62.3 64.2 2010 58.8 62.9 65.0 65.0 60.5 62.3 64.9 66.1 Infant mortality, rate per 1 000 LBa 1990 58.5 44.4 25.2 9.3 60.8 43.6 21.5 9.3 2010 26.8 18.4 12.6 10.4 24.2 16.7 13.2 6.5 Under-5 mortality, rate per 1 000 LB 1990 80.8 54.4 30.1 11.2 85.0 53.4 25.3 11.2 2010 42.4 22.0 15.0 11.8 36.3 19.3 15.1 7.5 Maternal mortality, rate per 100 000 LB 1990 308.1 100.2 117.9 18.4 289.9 122.8 71.0 12.4 2010 133.4 90.3 74.9 35.6 116.7 71.3 79.7 23.3 Source: prepared by authors from the study results. a LB = live births. whole. Life expectancy was directly cor- WS-related inequalities in healthy pared to a +40% reduction in the total related to social position defined by access to life expectancy life expectancy gap—an indication that improved sources of WS. Whereas absolute disability concentrated­ disproportion­ inequality—as ­assessed by both gap and Disability-free life expectancy also ately among those with the least access gradient metrics—­improved systematically improved, from 61.6 years in 1990 to to WS. The conforming rate of change and non-trivially between 1990 and 2010, 64.2 years in 2010—implying that, on between extreme quartiles of access to relative inequality did not. This pattern was average, over 50% of the gain in life ex- sanitation was around 30% in both life noted in the environmental hierarchy de­ pectancy accrued by the Region in that expectancy measurements. Relative fined by access to water, as well as in that by period stood for life lived with disabi- gaps remained invariant as well; overall, access to sanitation. Figure 1 depicts the case lity. The magnitude of inequality in around 50% of all potential years of life for the former: the SII went down from 12.8 healthy life expectancy among countries lost (to disability) stayed concentrated years (95%CI: 9.3 – 16.2) to 8.9 years (95%CI: across the environmental gradients de­ in the quartile of countries with the least 5.7 – 12.1), and the health concentration fined by access to water and sanitation access to WS. index (HCI) went up from −0.31 (95%CI: was less prominent than that of total life −0.44 – −0.17) to −0.50 (95%CI: −0.38 – −0.12). expectancy, but so was the rate of WS-related inequalities in infant In 2010, around 40% of all expected years of change in the period assessed. The abso- mortality life lost (to premature death) remained con- lute gap in healthy life expectancy be- centrated in the quartile of countries with tween extreme quartiles of water access The study found significant improve- least access to water (and 50% in those with narrowed by around 20% (from −7.6 ment in both the Regional mean level least access to sanitation). years in 1990 to −6.1 in 2010), as com­ and the extent of WS-related inequalities

FIGURE 1. Absolute (A) and relative (B) gradient inequalities in life expectancy at birth by access to water services, countries of the Americas (n = 33), 1990 and 2010 A Regression lines of health inequality B Concentration curves of health inequality 90 1.0 0.9 0.8 80 0.7 0.6 70 0.5 0.4 0.3 60

Life expectancy at birth (years) 0.2 1990 1990 Expected years of life lost (cumulative) 2010 0.1 2010 50 0.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Social position by access to drinking water Population gradient by access to drinking water

Source: prepared by authors from the study results.

350 Rev Panam Salud Publica 38(5), 2015 Mújica et al. • Water, sanitation, and health inequalities in the Americas Original research in the risk of dying before 1 year of age. −10.8) in 2010, and relative inequality DISCUSSION The infant mortality rate declined from shrunk from −0.34 (95%CI: −0.45 – −0.24) 29.0 (95%CI: 28.6 – 29.4) per 1 000 live to −0.29 (95%CI: −0.40 – −0.18). Similar Recent debate on the social determi- births in 1990 to 13.2 (95%CI: 13.0 – 13.5) changes were also observed across the nants of health has stressed the unequal in 2010. Absolute inequality, as mea­ sanitation­ access gradient, as shown in distribution of health as a major chal­ sured by the SII, improved from −59.7 Table 1. lenge for national development and (95%CI: −73.0 – −46.4) infant deaths per public health governance, as well as a 1 000 live births in 1990 to −19.6 WS-related inequalities in matter of environmental justice (9, 17, 18). (95%CI: −27.9 – −11.4) in 2010 in the po- maternal mortality This study contributes to that debate, pulation gradient defined by access to showing the fundamental role that access water, and from −59.8 (95%CI: −73.1 – Like the two other mortality outcomes to water and sanitation—as environmen- −46.6) infant deaths per 1 000 live births studied, maternal mortality and social po- tal determinants of health—has on the in 1990 to −22.2 (95%CI: −29.5 – −14.8) in sition defined by access to WS were found production and the perpetuation of 2010 in the population gradient defined strongly inversely correlated. On average, health inequality among countries of the by access to sanitation. Relative inequal­ the Regional maternal mortality ratio de- Americas. Access to drinking water and ity, as captured in the HCI, declined by creased from 86.7 (95%CI: 80.0 – 93.7) ma- improved sanitation facilities correlated 31% in the water access gradient and by ternal deaths per 100 000 live births in with survival and mortality, and during 26% in the sanitation access gradient, 1990 to 58.9 (95%CI: 54.1 – 64.1) in 2010; the period from 1990 – 2010, strong gra- ­reaching −0.22 (95%CI: −0.33 – −0.12) and i.e., a mere one-third reduction. Drops in dients were seen: the closer to universal −0.28 (95%CI: −0.38 – −0.17), respec­ absolute and relative inequality, both gap the access to WS, the higher the total and tively, in 2010. and gradient, were more pronounced — healthy life expectancies, and the lower the SII fell from −244.2 (95%CI: −339.7 – the infant, under-5, and maternal mortal­ WS-related inequalities in under-5 −148.6) maternal deaths per 100 000 live ity. The burden of total and healthy life mortality births in 1990 to −102.0 (95%CI: −144.2 – lost was unequally distributed across the −59.8) in 2010 across the sanitation population of the Region, being dispro- Patterns of magnitude and change- access gradient, and the HCI went down portionately concentrated among the over-time in Regional mean level and gap from −0.48 (95%CI: −0.62 – −0.35) to −0.28 most environmentally disadvantaged, and gradient inequalities analogous to (95%CI: −0.41 – −0.14]. Figure 2 illustrates who carried twice the burden than they those observed in infant mortality were the changes in absolute (SII) and relative would in a society with fairly distributed found as well in under-5 mortality. At the (HCI) inequalities in maternal mortality access to WS. In spite of the great strides Regional level, the risk of dying before across the environmental gradient defin­ed made toward improving Regional aver­ reaching 5 years of age dropped from 36.1 by access to improved sanitation facil­­ ages while narrowing health inequality (95%CI: 35.7 – 36.6) per 1 000 live births in ities. In 2010, roughly 44% of all maternal (largely absolute inequality) in life ex­ 1990 to 16.3 (95%CI: 16.1 – 16.6) in 2010. deaths accrued in the Region remained pectancies and maternal and child mor- Likewise, across the water access gra- disproportionately concentrated in the talities since 1990, this study suggests dient, absolute inequality shrunk from population quartile with the least access that socioeconomically deprived popula- −79.3 (95%CI: −97.0 – -61.5) per 1 000 live to sanitation, down from approximately tions in the Americas persistently suffer a births in 1990 to −29.7 (95%CI: −48.7 – 62% in 1990. steadily higher exposure to environmental­

FIGURE 2. Absolute (A) and relative (B) gradient inequalities in maternal mortality by access to sanitation services, countries of the Americas (n = 29), 1990 and 2010 A Regression lines of health inequality B Concentration curves of health inequality 300 1.0 1990 0.9

) 2010 lb

5 0.8 0.7 200 0.6 0.5 0.4 100 0.3

Maternal deaths (cumulative) 0.2

Maternal mortality (ratio per 10 1990 0.1 2010 0 0.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Social position by access to sanitation Population gradient by access to sanitation Source: prepared by authors from the study results.

Rev Panam Salud Publica 38(5), 2015 351 Original research Mújica et al. • Water, sanitation, and health inequalities in the Americas hazards and/or greater vulnerability to tude and changes over time of environ- (i) Policies ensuring universal access to their adverse effects on health. mentally-determined health inequali- safe water and sanitation, especially A growing concern on the environmen- ties in the Region of the Americas, for children under 5 years of age tal production of health inequality is albeit from an ecological perspective. living in low- and middle-income reflected in recent research and policy Ecological studies have several limita- areas, are critical; literature, although a focused interest of tions, including the fact that no causal or (ii) Improving the quality of water in the inquiry on water and/or sanitation as de- individual-level inferences can be made. home to have the greatest impact on terminants of health inequalities has To the extent that the generation of evi- the reduction of diarrhea in all age been rather limited. In the international dence in our study was grounded on ex- groups; context, some studies have found life ex- ploratory data analysis, i.e., oriented to (iii) Basic sanitation improvement, espe- pectancy, infant mortality, and maternal pattern extraction rather than confirma- cially excreta disposal, to effec­ mortality significantly associated with tory causal claims, we might have tively lower morbidity and mortality lack of water or sanitation facilities at the ­avoided the ecological fallacy (12). from diarrhea by 30% – 40%, notably household level (19, 20). A systematic Because of this focus on pattern extraction, when it is linked to community- ­ review of the evidence in Europe conclu- its analyses also privileged a bivariate level interventions to promote proper ded that socioeconomic inequalities in the rather than a multivariate approach, hygiene; living environment are major contribu- albeit acknowledging that exposure (iv) Sustainability and effectiveness of ting factors to health inequalities, and and vulnerability to lack of access to WS initiatives to improve WS condi- called for more and better research to are influenced by, and interact with, tions depend on behavioral changes quantify the magnitude of such environ- other determinants of health, such as in the population, such as hand mental in­equalities (21). A recent WHO/ age, gender, ethnicity, income, loca- washing; EURO-led European review also con­ tion, neighborhood infrastructure, (v) Available economic analyses show cluded that ­environmental health in- and living conditions (17–19, 21–26). that improvements in access to equalities are ever-present in all subre- Moreover, since the study was based WS are cost-effective. Time sav­ gions and countries, and are most often on secondary data sources, the validity ings are the main reason for the endured by disadvantaged­ population of its results are contingent on the qual­ economic ­benefits obtained, con- groups (22). Said review emphasized ity and reliability of those data sources tributing at least 80% of the interactions ­between lack of access to (5, 27, 28) gain (32). WS and income (­poverty), household type (single-­parent), and location (rural CONCLUSIONS In addition, strengthening national ­populations); nevertheless, it stated that statistical information systems and insti- tutional capacities to effectively monitor while the health impact of environmental­ Despite its limitations, some general social and environmental inequalities in and social conditions are documented in conclusions can be drawn from the health—and exposures to environmental some countries, the num­ber of relevant study to inform public policy. Even if hazards by equity stratifiers—should be studies is still low. the Region as a whole is on track to regarded as a priority and a core compo- There have been even fewer studies on meet MDG-7 on water and sanitation, nent of environmental equity and justice this issue in the Americas, particularly in there are large inequalities among in itself (18). LAC. In 2002, Soares and colleagues stud­ countries hidden by Regional averages. As the Region prepares to engage in the ied microdata from multipurpose house- Not only is progress towards the target transformative challenges for “people, hold surveys and showed the extent on sanitation the most off-track of all planet, prosperity, peace, partnership” that and ubiquity of inequalities in access to the MDGs (29), but since the advances were posed by the 2030 agenda for sustain­ and spending on drinking water servi- made are not equally distributed able development (33), water and sanita- ces: poorer and rural families had less throughout the population, inequity— tion must be recognized as core elements access to water supply and higher costs in the form of unjust, unfair, and avoid­ of human dignity. Water and sanitation and time consumed; however, no assess- able inequalities—needs to be addressed should be defended as fundamental ment of the impact on health inequality along with improving gross averages human rights and as global public goods. was reported (23). Two more recent stud­ so as to attain universal access to The principle of equity (34) must, there- ies found a significant association be- water and sanitation. Priority attention, fore, govern the actions on social inclu- tween higher sanitation (and water therefore, should be given to socially sion that are required to attain univer- supply) coverage and lower mortality in disadvantaged population groups, sal access to water and sanitation by children, (24) as well as improvements in partic­ularly through interventions 2030. public health infrastructure investments, aimed at decreasing exposure and including the provision of treated water ­vulnerability (18). and sewerage services, and positive Even though evidence of successful Acknowledgements. The authors trends in life expectancy­ (25). strategies for tackling environmental in- thank Mirta Roses Periago, Ana Treasure, equalities is scarce (17, 30), a PAHO sys- Jonathan Drewry, and Paulo Texeira Limitations tematic review on the effectiveness of WS for their valuable insights in pre- interventions in improving population vious versions of the manuscript. We To the best of our knowledge, this is health (31) identified some principles for also appreciate the financial support pro- the first study that reports on the magni- multisectoral action, namely: vided by PAHO/WHO, as part of

352 Rev Panam Salud Publica 38(5), 2015 Mújica et al. • Water, sanitation, and health inequalities in the Americas Original research its technical coopera­tion program on Conflict of interests. None. manuscript, which may not necessarily sustainable development and health reflect the opinion or policy of the RPSP/ Disclaimer. Authors hold sole respon- equity. PAJPH, and/or PAHO/WHO. sibility for the views expressed in this

REFERENCES

1. United Nations. World General Assembly situation in the Americas: basic indicators. mental and behavioural determinants of Resolution 64/292: The Human Right to Washington DC: PAHO; 1995–2012. ­childhood diarrhoea: analysis of two Water and Sanitation. New York: UN; 2010. 12. Tukey JW. Exploratory data analysis. cohort ­studies. Int J Epidemiol. 2008;37​ Available from www.un.org/es/comun/ Menlo Park: Addison-Wesley; 1977. (4):831–40. docs/?symbol=A/RES/64/292&lang=E 13. Schneider MC, Castillo C, Bacallao J, 27. Bain RES, Gundry SW, Wright JA, Yang H, Accessed on 4 June 2015. Loyola E, Mujica OJ, Roca A, et al. Pedley S, Bartram JK. Accounting for 2. World Health Organization/United Methods for measuring inequalities in water quality in monitoring access to safe Nations Children’s Fund Joint Monitoring health. Pan Am J Public Health. 2002;12(6): drinking-water as part of the Millennium Programme for Water Supply and 398–415. Development Goals: lessons from five Sanitation. Progress on Drinking Water 14. Maddala GS. Introduction to econome- countries. Bull World Health Organ. and Sanitation: 2012 Update. Geneva: trics. 3rd ed. Chichester (United Kingdom): 2012;90:228–35A. WHO; 2012. Available from www.ws- John Wiley & Sons; 2001. 28. Onda K, LoBuglio J, Bartram J. Global sinfo.org/ Accessed on 4 June 2015. 15. Murray CJL, Lopez AD. The global burden access to safe water: accounting for water 3. World Health Organization. UN Water of disease. Cambridge: Harvard University quality and the resulting impact on MDG Global Annual Assessment of Sanitation Press; 1996. progress. Int J Environ Res Public Health. and Drinking Water (GLAAS). 2012 Report: 16. Minujin A, Delamonica E. Mind the gap! 2012;9:880–94. the challenge of extending and sustaining Widening child mortality disparities. 29. Chan M. Keynote address: Universal access services. Geneva: WHO; 2012. Available J Human Dev. 2003;4(3):397–418. to water and sanitation: the lifeblood of from www.un.org/waterforlifedecade/pdf/​ 17. Brulle RJ, Pellow DN. Environmental good health. Proceedings of the Budapest glaas_report_2012_eng.pdf Accessed on 4 ­justice: human health and environmental Water Summit. 9 October 2013. Available June 2015. ­inequalities. Annu Rev Public Health. from: www.who.int/dg/speeches/​2013/ 4. Pan American Health Organization. 2006;27:103-24. water_sanitation/en/ Accessed on 4 June Volume I: Health in the Americas. 2012 ed. 18. Braubach M, Martuzzi M, Racioppi F, 2015. Washington, D.C.: PAHO; 2012. Krzyzanowski M. Understanding and ad- 30. Bambra C, Gibson M, Sowden A, Wright 5. Lim SS, Vos T, Flaxman AD, Danaei G, dressing the influence that social inequi- K, Whitehead M, Petticrew M. Tackling Shibuya K, Adair-Rohani H, et al. A com- ties have on environmental health. Euro the wider social determinants of health parative risk assessment of burden of J Public Health. 2010;20(1):12–3. and health inequalities: evidence from sys- ­disease and injury attributable to 67 risk 19. Hertz E, Hebert JR, Landon J. Social and tematic reviews. J Epidemiol Community ­factors and risk factor clusters in 21 regions,­ environmental factors and life expectancy, Health. 2010;64:284–91. 1990-2010: a systematic analysis for the infant mortality, and maternal mortality 31. Pan American Health Organization. Water Global Burden of Disease Study 2010. Lancet. rates: results of a cross-national compari- and sanitation: evidence for public policies 2012;380(9859):2224–60. son. Soc Sci Med. 1994;39(1):105–14. focused on human rights and public health 6. Wolf J, Prüss-Ustün A, Cumming O, 20. Fink G, Günther I, Hill K. The effect of water results. Washington, D.C.: PAHO; 2011. Bartram J, Bonjour S, Cairncross S, et al. and sanitation on child health: evidence from 32. Hutton G, Haller L, Bartram J. Global Assessing the impact of drinking water and the demographic and health surveys 1986- cost-benefit analysis of water supply and sanitation on diarrhoeal disease in low- and 2007. Int J Epidemiol. 2011;40:1196–204. sanitation interventions. J Water Health. middle-income settings: systematic review 21. Bolte G, Tamburlini G, Kohlhuber M. 2007;5(4):481–502. and meta-regression. Trop Med Int Health. Environmental inequalities among children 33. United Nations General Assembly. Reso­ 2014;19(8):928–42. in Europe – evaluation of scientific evidence lution A/RES/70/1: Transforming our 7. Humphrey JH. Child undernutrition, tropi- and policy implications. Euro J Public world: the 2030 Agenda for Sustainable cal enteropathy, toilets, and handwashing. Health. 2009;20(1):14–20. Development. 25 September 2015; New Lancet. 2009; 374(9694):1032–5. 22. World Health Organization, Regional York: United Nation;, 2015. Available from: 8. Water Aid. Abandoning open defecation: Office for Europe. Environmental health in- www.un.org/ga/search/view_doc.as- comparison and adaptation of social equalities in Europe. Copenhagen: WHO- p?symbol=A/RES/70/1&Lang=E change dynamics. Accra: Water Aid Ghana; EURO; 2012. Accessed on 2 October 2015. 2010. Available from www.wateraid.org/ 23. Soares LCR, Griesinger MO, Dachs JN, 34. Becerra-Posada F. Health equity: the linch- documents/plugin_documents/social_ Bittner MA, Tavares S. Inequities in access pin of sustainable development. Pan Am J transformation_study_briefing_note.pdf to and use of drinking water services in Public Health. 2015;38(1):5–8. Accessed on 4 June 2015. Latin America and the Caribbean. Pan Am 9. Marmot M. Closing the gap in a genera- J Public Health. 2002;11(5/6):386–96. tion: health equity through action on the 24. Teixeira JC, Gomes MHR, Souza JA. social determinants of health. Final report Association between sanitation services co- of the Commission on Social Determinants verage and epidemiological indicators in of Health. Geneva: WHO; 2008. Available Latin America: a study with secondary data. from http://apps.who.int/iris/bitstream/​ Pan Am J Public Health. 2012;32(6):419–25. Manuscript received on 3 November 2015. Revised 10665/43943/1/9789241563703_eng.pdf 25. Soares RR. Life expectancy and welfare in version accepted for publication on 20 November Accessed on 4 June 2015. Latin America and the Caribbean. Health 2015. 10. Mujica OJ. Eco-Epidemiology. In: Boslaugh Econ. 2009;18(1):S37–54. S, ed. Encyclopedia of epidemiology. Thou­ 26. Genser B, Strina A, dos Santos LA, Teles sand Oaks: Sage Publications; 2008. CA, Prado MS, Cairncross S, et al. Impact 11. Pan American Health Organization. of a city-wide sanitation intervention in a PAHO Core Health Data Initiative. Health large urban centre on social, environ­

Rev Panam Salud Publica 38(5), 2015 353 Original research Mújica et al. • Water, sanitation, and health inequalities in the Americas

RESUMEN Objetivo. Explorar la desigualdad distributiva de resultados clave en salud ­determinada por la cobertura de acceso a agua y saneamiento (AS) entre países en la Región de las Américas. Gradientes de acceso Métodos. Se diseñó un estudio ecológico para explorar la magnitud y el cambio en el a agua y saneamiento y tiempo de métricas estándar de brecha y gradiente de desigualdades ambientales en salud a nivel país en 1990 y 2010 entre los 35 países de las Américas. El acceso a agua desigualdades en salud potable y el acceso a instalaciones sanitarias mejoradas fueron seleccionados como entre los países de la Región estratificadores de equidad. Las cinco variables dependientes fueron: expectativa de de las Américas, 1990 y 2010 vida al nacer total y saludable, mortalidad infantil, en menores de cinco años y materna. Resultados. El acceso a AS se correlacionó con la supervivencia y mortalidad y se observaron intensos gradientes tanto en 1990 como en 2010. Un acceso a AS más alto se correspondió con más alta expectativa de vida al nacer total y saludable y con más bajos riesgos de muerte infantil, en menores de 5 años y materna. La carga de vida perdida se distribuyó inequitativamente, concentrándose de manera sostenida entre los más desaventajados ambientalmente, quienes acarrearon hasta dos veces la carga que hubieran acarreado si el acceso a AS hubiese estado equitativamente distribuido. Los promedios poblacionales en la expectativa de vida y la mortalidad específica mejoraron pero, mientras que las desigualdades absolutas se redujeron, las ­desigualdades relativas se mantuvieron esencialmente invariantes. Conclusiones. Aún cuando la Región está en curso para alcanzar el ODM 7 sobre agua y saneamiento, los promedios regionales siguen ocultando grandes ­gradientes ambientales y desigualdades en salud entre países. A medida que se despliega la agenda de desarrollo post-2015, serán necesarias políticas y acciones ­orientadas a la equidad en salud —principalmente hacia aquellos con mayor privación social y ambiental— a fin de asegurar el derecho por el acceso universal al agua y saneamiento.

Palabras clave Desigualdades en la salud; agua; saneamiento; salud ambiental; determinantes sociales de la salud; Objetivos de Desarrollo del Milenio; Objetivos de Desarrollo Sostenible; Américas.

354 Rev Panam Salud Publica 38(5), 2015